A good A1C for someone without diabetes is below 5.7%, which translates to an average blood sugar of roughly 117 mg/dL or less over the previous two to three months. If you have diabetes, the most widely used target is below 7%, though your ideal number depends on your age, overall health, and risk of low blood sugar episodes.
The Standard A1C Ranges
The A1C test measures the percentage of your red blood cells that have glucose attached to them. Because red blood cells live about three months, the test captures a rolling average of your blood sugar rather than a single snapshot. Three categories define where you stand:
- Normal: below 5.7%
- Prediabetes: 5.7% to 6.4%
- Diabetes: 6.5% or above
A result in the prediabetes range means your blood sugar is higher than normal but not yet high enough for a diabetes diagnosis. It’s a window where lifestyle changes, particularly losing a modest amount of weight and increasing physical activity, can often bring numbers back down. Any test used to diagnose diabetes requires confirmation with a second measurement unless you already have clear symptoms like excessive thirst, frequent urination, or unexplained weight loss.
What A1C Means in Everyday Blood Sugar
A1C percentages can feel abstract. Converting them to estimated average glucose (eAG) in mg/dL makes the number more concrete, especially if you check your blood sugar at home. The formula is straightforward: multiply your A1C by 28.7, then subtract 46.7.
- 6% = about 126 mg/dL
- 6.5% = about 140 mg/dL
- 7% = about 154 mg/dL
- 7.5% = about 169 mg/dL
- 8% = about 183 mg/dL
- 9% = about 212 mg/dL
- 10% = about 240 mg/dL
So if your A1C comes back at 7%, your blood sugar has been averaging around 154 mg/dL over the past two to three months. That context helps you connect the lab number to what your meter shows day to day.
A1C Goals if You Have Diabetes
The American Diabetes Association sets the target for most non-pregnant adults with diabetes at below 7%. That level is associated with a meaningfully lower risk of complications affecting the eyes, kidneys, and nerves. It’s the benchmark most primary care doctors use when reviewing your labs.
The American Association of Clinical Endocrinologists recommends a tighter goal of 6.5% or below for people who can reach it safely, meaning they don’t have frequent low blood sugar episodes or other serious health conditions. In practice, this tighter target works best for people diagnosed relatively recently who respond well to treatment.
On the other end, a looser target of 7% to 8% is often more appropriate for people who have a history of severe low blood sugar, advanced kidney disease, multiple chronic illnesses, or a shorter life expectancy. Pushing too aggressively toward a lower number in these situations can do more harm than good. The American Geriatrics Society echoes this, recommending that targets for older adults be individualized: below 7% for those who are relatively healthy with good functional status, and more relaxed for frail older adults or those with a life expectancy under five years.
The core point is that “good” looks different depending on your circumstances. A 35-year-old recently diagnosed with type 2 diabetes and no complications has a different ideal A1C than a 78-year-old managing diabetes alongside heart failure.
A1C Targets During Pregnancy
Pregnancy tightens the numbers considerably. The American College of Obstetricians and Gynecologists recommends that pregnant women with type 1 or type 2 diabetes keep their A1C at or below 6%. Higher levels raise the risk of complications for both the mother and the baby, including preterm birth and abnormal fetal growth. Because A1C reflects a weeks-long average, doctors typically check it more frequently during pregnancy to make sure blood sugar management is staying on track.
Can A1C Be Too Low?
For people without diabetes, a low A1C simply reflects normal blood sugar. But for people on diabetes medications, an A1C below 6% sometimes raises concern that blood sugar is dipping too low too often. Some clinicians have worried that very low A1C levels in treated patients could signal dangerous hypoglycemia and increase the risk of death. However, a study published in PLOS ONE found that after accounting for kidney function and anemia, there was no significant link between low A1C and higher mortality in people with diabetes. The study also found that hypoglycemia episodes were actually more common in people with A1C levels between 7% and 9.9% than in those below 7%.
That said, the risk isn’t zero. If your A1C drops well below your target and you’re taking insulin or medications that stimulate insulin release, it’s worth reviewing whether your treatment needs adjusting, especially if you’re experiencing symptoms like shakiness, confusion, or sweating between meals.
When the A1C Test Can Be Inaccurate
The A1C test measures glucose attached to hemoglobin, so anything that changes your hemoglobin or red blood cell turnover can skew the result. Iron-deficiency anemia, sickle cell trait, significant blood loss, recent blood transfusions, and advanced kidney disease can all push your A1C reading artificially higher or lower than your actual average blood sugar. If you have any of these conditions, your doctor may rely more heavily on direct blood sugar measurements or alternative tests like fructosamine, which reflects a shorter window of blood sugar control.
Certain hemoglobin variants, more common in people of African, Southeast Asian, or Mediterranean descent, can also interfere with some A1C testing methods. If your A1C doesn’t match what your daily blood sugar readings suggest, this is one possible explanation worth investigating.
How Often to Get Tested
If your blood sugar is well controlled and stable, testing twice a year is typically sufficient. If you’ve recently changed medications, aren’t meeting your target, or have just been diagnosed, your doctor will likely check every three months. For people with prediabetes, annual testing helps catch any progression early enough to intervene. Since the test reflects the previous two to three months, testing more frequently than every three months won’t give you meaningfully new information.